Digital signals supposedly can only assume two values, high or low. This is the basis of all modern electronics and makes things much simpler in many ways. The high and the low voltage levels are arbitrary but low is typically ground and high is usually, but not always, whatever the highest voltage in the circuit is. With a digital circuit, you get certain benefits such as greater immunity to noise and the ability to encode data in different ways. Of course, in reality, digital signals are made up of analog signals, so there are still those challenges to consider if you’re working at that level.
Characterized by a process in which a variable takes on either of two values.
Electronic Devices : Conventional Current Version, 9th Edition by Thomas L. Floyd